Abstract: The optimization experiment of active polysaccharide extraction of Chinese yam was carried out and the optimal extraction condition was determined, and accordingly to be used in extracting of Chinese yam polysaccharide in this articles. The experiment of yam polysaccharide yield as an index for yam pretreatment time was studied, extraction temperature, extraction time, material-water mass ratio and extraction times, repeatability, recovery and reuse of solvent and other factors in the extraction process were studied, finally the experimental results were analysied by orthogonal. The results showed that the better pre-processing time for yam polysaccharide extraction was 2+2h, extraction time was 2h, extraction temperature was
60℃, material-water ratio was 1:20, extraction times was 1; repeatability for extraction operation was good, recycling solvents were feasible. The better conditions are obtained by orthogonal design as follows: extraction temperature 65 ℃, extraction time 2.5 hours and material-water mass ratio 1:25.
Key words: Yam polysaccharide; Extraction process; Yield; Solvent recovery; Orthogonal design